Air cleaner; replaceable filter cartridges; and, methods

ABSTRACT

The disclosure concern air cleaners. Preferred air cleaners are shown which include a housing and a removable and replacement primary filter cartridge. Optional and advantageous features are shown. An optional mechanical interlock, operated with a non-threaded, movement of the cartridge, is provided between the primary filter cartridge and the housing. The preferred primary filter cartridge is conical in shape. A preferred optional safety or secondary filter cartridge is shown. Preferred methods of assembly and use are provided.

CROSS-REFERENCE TO RELATED APPLICATION AND PRIORITY FILINGS

This application is a continuation of U.S. patent Ser. No. 10/691,856filed Oct. 23, 2003 now U.S. Pat. No. 7,070,642, which application ishereby incorporated by reference in its entirety. A claim of priorityfrom U.S. patent Ser. No. 10/691,856 is incorporated herein to theextent appropriate. U.S. Ser. No. 10/691,856 issued as U.S. Pat. No.7,070,642 on, on Jul. 4, 2006.

The parent disclosure claims priority to U.S. Provisional ApplicationNo. 60/421,882 filed Oct. 28, 2002; and U.S. Provisional Application No.60/453,737 filed Mar. 6, 2003, both of which are incorporated herein byreference. A priority right, to the extent appropriate, is claimed fromeach of the two identified provisional applications.

FIELD OF THE DISCLOSURE

The present disclosure concerns air cleaners. It particularly concernsair cleaners with removable and replaceable (i.e., serviceable) filtercartridges. The particular arrangement disclosed uses a first stageseparator or precleaner, to facilitate operation. Methods of assemblyand use are also provided.

BACKGROUND

Air filtering is used in a variety of arrangements. A typicalapplication is as an air cleaner for intake air to internal combustionengines. After a period of use, filter media within the cleaner requiresservicing, either through cleaning or complete replacement. Typically,for an air cleaner used with an internal combustion engine such as on avehicle, filter media is contained in a removable or replaceable (i.e.,serviceable) component, element or cartridge. Examples are shown in U.S.Pat. Nos. 4,211,543; 4,135,899; 3,672,130; B1 5,445,241; 5,700,304;6,051,042; 6,039,778; 5,547,480; 5,755,842; and 5,800,581; and PCTpublication WO 89/01818; the complete disclosures of all of thesereferences being incorporated herein by reference. U.S. application Ser.No. 09/729,033 filed Dec. 4, 2000 also shows such an element, with aunique interaction shown between the element and an end cover. Thedisclosure of the Ser. No. 09/729,033 application is also incorporatedherein by reference.

Improvements in filter arrangements relating to assembly and use, aredesirable.

SUMMARY

The present disclosure concerns improvements in air cleaners. Thetechniques are particularly developed for use with air cleaners forcleaning engine air intake for an internal combustion engine, such asused with a vehicle such as a bus, truck or mobile equipment such as atractor or construction equipment, or a stationary generator. Theimprovements generally relate to air cleaners in which filter media ispart of a removable and replaceable (i.e., serviceable) component.

A number of improvements are brought forward by the present disclosure,and in the figures embodiments depicting examples of the variousimprovements described, are provided. However, it is not necessary thatall of the possible improvements described be incorporated in any givenair cleaner system or component; and, variations from the embodimentsdescribed are possible.

Many of the improvements relate to unique possible constructions ofprimary filter element cartridges. Examples of these optionalimprovements, described in detail below, include:

-   -   1a. An improved construction that, among other things, allows        optional use of an outer support in the primary filter        cartridge; and, no inner support that extends the entire length        of the element, for pleated media;    -   2a. Improved constructions relating to a manner in which the        primary filter cartridge is secured to, and is sealed to, an air        cleaner housing;    -   3a. An improvement in an outer support framework of such a        cartridge, relating to: (a) a shielded area for use in        connection with a dust evacuator; and, (b) a porous area, for        permitting air flow to the media in a preferred manner;    -   4a. An improved shape, to accommodate certain housing features;    -   5a. An improved interlock at a closed end of the filter, to        inhibit rotational movement of the filter during use; and    -   6a. Improvement in an outer framework structure to facilitate        cartridge manufacture and assembly.

Optional improvements provided herein also relate to structurecircumscribed by the primary filter cartridge during use. Some of theseoptional improvements relate, for example, to the following:

-   -   1b. A preferred support, separately mountable within the air        cleaner assembly from the primary filter cartridge, to operate        as an inner support for pleated media;    -   2b. Optional incorporation of the support identified at 1b        above, as a support, for example as an outer support, for a        preferred safety filter cartridge;    -   3b. Improved and advantageous arrangements for securing the        support and/or secondary filter cartridge to an air cleaner        housing;    -   4b. An improved optional interaction between inner and outer        liners of a safety element cartridge; and,    -   5b. An optional improved shape/fit relation between a safety        element or inner support, and a primary filter cartridge.

In addition, improvements described herein are also provided withrespect to an air cleaner housing. Some of the improvements, forexample, relate to the following:

-   -   1c. Features in the housing to facilitate preferred independent        mounting of a primary filter cartridge and inner support (or        optional safety filter cartridge);    -   2c. An optional jointed housing sidewall, to permit change in        orientation of housing components, such as an inlet angular        orientation relative to a dust flow outlet;    -   3c. Preferred locations of inlet, outlet and dust ejector tubes;    -   4c. An improved optional end cover mountable through a        non-rotational lock fit arrangement that does not necessarily        require added latches or similar constructions;    -   5c. An improved precleaner arrangement optionally secured to an        end cover;    -   6c. An improved, optional, cover which is mounted circumscribed        by a portion of the housing, as opposed to having a portion of        the cover overlapping a portion of the housing;    -   7c. An improved, optional, rotational, indexing between the        cover and the housing; and,    -   8c. A cover which can include an improved member of a        projection/receiver mechanism, to inhibit undesired rotation of        an associated primary filter cartridge, during use.

Herein, improvements in a housing end cover, associated with an aircleaner housing sidewall, are also provided. Some of these optionalimprovements, for example, relate to the following:

-   -   1d. Provision of a closed end cover which optionally includes a        precleaner permanently mounted thereon;    -   2d. A closed end cover with an optional integrally molded latch        mechanism for non-rotational engagement with a housing sidewall,        during use;    -   3d. A particular optional flexible tab/latch mechanism        engageable with an end cover through a tongue/slot interference        fit;    -   4d. An improved, optional, indexing arrangement for securing an        end cover to a housing sidewall;    -   5d. An improved, optional, mounting arrangement in which an end        cover is mounted with a portion of the housing sidewall        circumscribing the end cover and without a portion of the end        cover circumscribing the housing sidewall; and    -   6d. An improved, optional, interlock arrangement on the end        cover, for engaging a portion of an associated primary filter        cartridge, in use.

Also provided herein are improvements in use.

It will also be apparent from the detailed discussion, that thepreferred components can be configured to facilitate manufacture andassembly. Examples of some of these optional improvements include thefollowing:

-   -   1e. An improved, optional, outer support for a primary filter        cartridge that facilitates manufacture;    -   2e Preferred optional housing components, including features as        described above, in configurations that can be readily        manufactured using plastics molding techniques;    -   3e. Preferred optional techniques of mounting and sealing a        primary filter cartridge in a housing;    -   4e. Preferred optional techniques of mounting and sealing a        secondary filter or safety filter cartridge, in a housing; and,    -   5e. Improved and preferred, optional, techniques for supporting        media in a primary filter cartridge.    -   6e. Improved and preferred (optional) techniques for supporting        media in a secondary or safety filter cartridge.

Specific examples of features that provide for the above, are shown inthe drawings and are described in the detailed description below. Ingeneral, individual ones are usable, to provide improvement. In thepreferred embodiments depicted, selected one of the various features arecoordinated together, in a unique, improved, air cleaners and in uniqueair cleaner componentry arrangements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side perspective view of a filter assembly according to thepresent disclosure;

FIG. 2 is an exploded perspective view showing removable componentry,from the assembly of FIG. 1;

FIG. 3 is a side cross-sectional view of the assembly of FIGS. 1-2depicted without a removable dust evacuator valve;

FIG. 4 is an enlarged, exploded, fragmentary outside perspective view ofan end cover component and a primary filter cartridge, of the assemblyof FIG. 1;

FIG. 5 is an enlarged, exploded inside perspective view of thecomponents depicted in FIG. 4;

FIG. 6 is a side elevational view of a primary filter cartridgecomponent of the assembly of FIG. 1;

FIG. 7 is an end view of the filter cartridge depicted in FIG. 6 lookingtoward end 58;

FIG. 8 is a perspective view of a component of the filter cartridgedepicted in FIGS. 6-7;

FIG. 9 is an end elevational view of a housing component of the assemblydepicted in FIG. 1, shown with an end cover component removed and withcertain internal componentry viewable;

FIG. 10 is a side cross-sectional view of the housing component of FIG.9 taken generally along line 10-10, FIG. 9;

FIG. 11 is a side elevational view of a safety element component of theassembly of FIG. 1;

FIG. 12 is a side cross-sectional view of the safety element componentof FIG. 11 taken along line 12-12, FIG. 11;

FIG. 13 is an exploded view of the safety element component of FIG. 11;

FIG. 14 is a side perspective view of an alternate embodiment of an aircleaner according to the present disclosure;

FIG. 15 is a fragmentary, perspective, view of a second alternateembodiment of an air cleaner according to the present disclosure;

FIG. 16 is an end view of a portion of a third alternate embodiment ofan air cleaner according to the present disclosure;

FIG. 17 is a side, cross-sectional view taken generally along line17-17, FIG. 16;

FIG. 18 is an enlarged, fragmentary view of a portion of the arrangementshown in FIG. 17, with a safety element mounted therein;

FIG. 19 is a perspective view of a fourth alternate embodiment of an aircleaner according to the present disclosure;

FIG. 20 is a fragmentary, perspective view of a portion of an alternateprimary element usable in an air cleaner according to the presentdisclosure;

FIG. 21 is a fragmentary, cross-sectional view of an alternate primaryfilter element according to the present disclosure;

FIG. 22 is a perspective view of a further alternate air cleaner housingaccording to the present disclosure; and,

FIG. 23 is a fragmentary, cross-sectional view of a portion of FIG. 22.

FIG. 24 is a schematic, perspective view of a further alternate aircleaner according to the present disclosure.

FIG. 25 is an exploded, schematic, perspective view depicting a covermember and a primary air filter element cartridge of the assembly ofFIG. 24.

FIG. 26 is a side elevational view of the primary filter elementcartridge depicted in FIG. 25.

FIG. 27 is a side, cross-sectional view of the assembly depicted in FIG.24.

FIG. 28 is an inlet end perspective view of further embodiment of an aircleaner according to the present disclosure.

FIG. 29 is an exploded perspective view of the arrangement depicted inFIG. 28.

FIG. 30 is a perspective view of two of the components depicted in FIG.29, from a view point toward an inside surface of an inlet end cover.

FIG. 31 is a side, cross-sectional view of the assembly depicted in FIG.28.

FIG. 32 is a side elevational view of primary filter element componentusable in the assembly of FIGS. 28-31.

FIG. 33 is a perspective view of an outer framework component useable inthe primary filter element depicted in FIG. 32.

DETAILED DESCRIPTION

The present disclosure concerns an air cleaner configuration. A varietyof enhancements to prior art air cleaners is provided. Various ones, orselected ones, of the enhancements can be used to provide a useful aircleaner. The particular air cleaner depicted in FIG. 1-13, and thealternates of FIGS. 14-33 show or demonstrate examples of many of thevarious enhancements described herein. There is no requirement that inany and all practices of the techniques and principles of the presentenclosure, all of the enhancements described need to be used. Many ofthe features are described in co-owned, copending, U.S. Provisionalapplications 60/421,882, filed Oct. 28, 2002 and 60/453,737 filed Mar.6, 2003, each of the two identified U.S. provisional applications beingincorporated herein by reference.

I. General Air Cleaner Configuration and Operation

The reference numeral 1, FIG. 1, generally represents an air cleanerassembly according to the present disclosure. The particular air cleanerassembly 1 depicted, is an engine combustion air intake air cleanerassembly 2. Many of the techniques described herein can be applied inthe filtering or cleaning of a variety of gases. However, the detailsdisclosed were particularly developed for application in an air cleanerassembly, for example for use to clean engine intake air for an internalcombustion engine, such as the engine of a vehicle such as a truck, bus,tractor or construction equipment; or for a generator.

Referring to FIG. 1, air cleaner assembly 2 generally comprises ahousing 3 having: an air inlet 5; an air outlet 6; and, a dust ejectoror drop tube 7. The air cleaner assembly 2 also includes optionalmounting legs or supports 8 thereon to facilitate mounting.(Alternatively, the assembly 2 could be mounted with a separate mountingband or bracket.) It is anticipated that the typical orientation for thehousing 2 depicted in FIG. 1, in use, will be generally horizontal(i.e., with tube 6 extending horizontally, as generally shown in FIG. 1,with drop tube 7 pointing down). However, many of the principles andtechniques described herein can be applied to air cleaner assembliesmounted in other orientations.

The particular housing 2 depicted has a generally cylindrically shapedouter housing sidewall 9; i.e., sidewall 9 is generally circular incross-section. The air inlet 5 for the embodiment shown is a side entry5 a, i.e., entry 5 a goes through sidewall 9. Specifically, inlet 5 is acircular, tangential, inlet 10. The term “tangential” in this context ismeant to indicate that a center line 11 of the circular inlet 10 is notdirected toward a center axis 12, FIG. 3, of the housing 3, but rather,center line 11 is directed more tangentially. This will cause the airentering through tangential inlet 10 (and thus directed into region 14,FIG. 3), to begin movement in a swirling pattern. The swirling patternis facilitated by the preferred, generally cylindrical, shape tosidewall 9.

Still referring to FIG. 1, air outlet 6 is a circular, axial, outlet 15.By “axial” in this context, it is meant that a center line of outlet 15,FIG. 3, extends parallel to a center line or axis 12, FIG. 3, of housing3. In the particular instance shown, the center line of outlet 15 iscoaxial with the center line 12 of housing 3, because the preferredhousing sidewall 9 has a circular cross-section and the outlet 6 is noteccentrically positioned. Of course, alternate configurations arefeasible, but this particular one is convenient. The reference to outlet15 being circular, is a reference to the general shape of the interiorair flow conduit.

Referring to FIG. 3, the sidewall 9 has first and second opposite ends16 and 17 respectively. First end 16 is closed by cover 18 having outlet6 projecting therefrom. Referring to FIG. 3, cover 18 is integral with,and is not separable from, end 16, and, in the preferred configurationshown cover 18 has at least two, in this instance at least three regionsor steps of different diameter, indicated at 18 a, 18 b and 18 c. Thecorresponding internal diameters or steps decrease with 18 a>18 b>18 c.The function of these steps will be understood from further discussions.

Tap 6 a, in outlet tube 6, is for attachment of optional pressure orrestriction indicators or other equipment.

For the particular embodiment shown, dust drop tube 7 is adjacent firstend 16.

End 17, FIG. 1, defines an open end, and air cleaner 2 includes inlet 5adjacent thereto. The open end 17 in the sidewall 19 is closed topassage of air therethrough by cover 20.

In general, cover 20 has no aperture therethrough in the end region 20a, and is a removable access or service cover 21 mounted on sidewall 9to close end 17. Service cover 21 is periodically opened or removed, toprovide service access to an interior 23, FIG. 3, of housing 3, forinspection, service or mounting of componentry contained therein. Forthe particular embodiment depicted, the service cover 21 is completelyremovable from sidewall 9, for service access to interior 23. The cover21 can be secured to a remainder 25 (FIG. 10) of housing 3, in a varietyof ways, for example through the use of latches, bolts or otherconstructions. Several, convenient, mounting mechanisms are shown andare discussed in detail below.

Attention is now directed to FIG. 2. In FIG. 2, air cleaner assembly 2is depicted in exploded perspective view, so that certain separablecomponentry is viewable. Referring to FIG. 2, the componentry depictedincludes: housing section 25 (i.e., the housing 3 without the cover 20);service cover 21; a removable and replaceable primary filter element orfilter cartridge 30; optional removable and replaceable secondary safetyfilter element or cartridge 31; and, dust evacuator valve 32 (shown inphantom and not shown removed). Primary cartridge 30 is depicted in sideelevational view in FIG. 6; and, safety cartridge 31 is depicted in sideelevational view in FIG. 11. The dust evacuator valve 32 is removable,but in normal use of air cleaner 2, once installed valve 32 is notremoved unless it becomes damaged.

Still referring to FIG. 2, the air cleaner assembly 2 further includes aprecleaner 35. In general, a precleaner such as precleaner 35, operatesto remove certain particulate material from an air stream, before theair stream is passed into media of the primary air filter element orcartridge 30. An advantage from this, is that it provides for longeroperational life of the primary filter cartridge 30. For the particulararrangement depicted, the precleaner 35 is secured to the service cover21, and in normal, preferred, operation is never separated and indeed isnot separable without causing damage to the cover 20. In an alternateembodiment, discussed below in connection with FIG. 21, the precleaneris mounted on, and is secured to, the primary filter element orcartridge.

Referring to FIG. 5, the precleaner 35 includes: a cyclonic rampcomponent 36; and, a generally cylindrical shield component 37; with theramp 36 positioned on an outer surface 42 of the shield 37. In theembodiment shown, ramp 36 and shield 37 are integral with one another,the two being molded together as a single plastic piece. At end 36 a,region 36 b behind ramp 36 (i.e., between ramp 36 and end 20 a of cover20) ramp 36 is closed by end 38. Operation of components 36, 37 (andthus precleaner 35) will in part be understood by reference to generaloperation of the air cleaner assembly 2.

During normal operation, air to be filtered enters air cleaner assembly2 through tangential inlet 10, FIG. 1 into space 14, FIG. 3. The space14 is generally defined as being between inside surface 41 (of housingsidewall 9), and outside surface 42 (of shield 37). The entrance intospace 14 is preferably into one of regions 43 a, 43 b, FIG. 5, whereramp 36 has not progressed away from end 20 a substantially. Because ofthe preferred tangential entry, the air flow directed into space 14 isgenerally directed into a circular, circumferential or cyclonic flow.For the particular embodiment shown, and referring to the general viewpoint of FIG. 1, when looking toward cover 20 from the outside of aircleaner 2, this flow would be clockwise. Of course the air cleanerassembly 2 could be configured for an opposite direction of flow.

Referring again to FIG. 3, upon entering space 14, the air is directedinto the precleaner 35. Cyclonic ramp 36 is positioned to help impart aspiral or cyclonic moment to the air and dust carried therein spiralingtoward end 16, as the air circles around shield 37. In general the ramp36 coils around shield 37 less than one full turn, preferably no morethan 340°, typically less than 320°, for example an amount within therange of 150° to 280°. A typical shield 37 would project at least 35 mm.(millimeters) and typically 44 mm. to 170 mm. along the side of theelement cartridge 30. A typical ramp 36 would project at least 5 mm. andtypically 7 mm.-20 mm. outwardly from shield 37.

The shield 37 prevents the air, carrying particles, from immediatelyimpacting the media in cartridge 30, before spiraling (and thusprecleaning) occurs. In general, as a result of the cyclonic spin, asubstantial portion of the dust particles carried within the air streamwill be directed toward inside wall 41 of housing 15, eventually to beejected through dust drop tube 7. In a typical arrangement, dust droptube 7 would be covered by an ejector valve 32, shown in phantom inFIGS. 1 and 2. Such ejector valves are well known. Some examples aredescribed in U.S. Pat. No. 3,429,108, the complete disclosure of whichis incorporated herein by reference.

In a typical embodiment, the ramp 36 spirals at a rate providing about 2mm. to 4 mm. linear movement or distance away from end 43, per 10° ofturn.

Referring to FIGS. 3 and 5, in general the primary element or cartridge30 comprises an extension of media 55 which circumscribes and defines acentral clean air volume 56. For the particular embodiment depicted, themedia 55 is arranged in pleats 55 a which extend longitudinally betweenends 57, 58 of the cartridge 30.

Referring again to FIG. 3, after exiting precleaner 35 the air passesthrough primary cartridge 30 from upstream side 59 to downstream side60, and then enters clean air region 56. The air at this point istypically sufficiently clean to be passed on through outlet tube 6, tothe engine/air intake of an internal combustion engine.

As mentioned above, the particular air cleaner assembly 2 depicted,includes an optional secondary or safety element or cartridge 31, FIG.2. The safety element or cartridge 31 comprises media 65 positioned inregion 56, FIG. 3, such that air exiting media 55 must pass throughmedia 65 on the way to outlet 6. Media 65 for a typical application, isnot pleated, but rather comprises a sheet of non-woven fibrous mediawhich circumscribes open central area 66, FIG. 3.

From the above description, general operation of the air cleanerassembly 2 will be understood to be as follows:

-   -   1. Air to be filtered first enters the assembly 2 through inlet        5.    -   2. Through a combination of tangential entry, the circular        housing sidewall 9, shield 37 and the precleaner ramp 36, the        air stream is directed into a cyclonic or spiral flow pattern.        This drives some of the dust material against the inside surface        41 of the housing sidewall 9, providing a precleaning effect.        The precleaned dust is eventually ejected through down tube 7.    -   3. The air passes through the media 55 of the primary filter        cartridge 30, and is filtered thereby.    -   4. If the optional safety or secondary filter cartridge is used,        the filtered air then passes through media 65 of the safety or        secondary filter cartridge 31, into clean air region 66.    -   5. The air is then directed axially outwardly from air cleaner        2, through end cover 18, i.e., through outlet duct 6.

Also, certain general structural features of the preferred air cleanerassembly 2 are as follows:

-   -   1. The access cover 20 is located at opposite end 17 of the        housing 3 from the air flow outlet tube 6.    -   2. The inlet 5 is a side entry inlet, and the outlet 6 is an        axial airflow outlet.    -   3. The inlet 5 is located adjacent end 17 of the housing, and        the outlet tube 6 is located adjacent opposite end 16 of the        housing 3.    -   4. The down tube 7 for the dust is located adjacent outlet tube        6 and end 16 of the housing.    -   5. Precleaner 35 is located adjacent inlet tube 5 at end 17 of        the housing, and thus adjacent cover 20.    -   6. For the particular embodiment of FIG. 3, the precleaner 35 is        permanently mounted on cover 20.

II. Sealing of the Primary Filter Cartridge 30 within Air Cleaner 2

As discussed above, primary filter cartridge 30 is a removable andreplaceable (i.e., serviceable) component. That is, primary filtercartridge 30 is constructed to be removable for servicing (for exampleby replacement). In order to ensure proper operation of air cleanerassembly 2, it is thus necessary that the primary cartridge 30 beconstructed for appropriate sealing within housing 3, once installed, sothat air does not bypass the media 55 during operation. The air cleanerassembly 2 can be configured to provide for this seal in a variety ofmanners.

For example, a radial seal between either an internal portion orexternal portion of the primary element 30, around its outlet end, andanother portion of the assembly, could be used. Various types of radialseal systems, adaptable for air cleaners which include componentryhaving certain features as described herein, are shown for example inPCT Publication WO 89/01818 at 259 and in U.S. Pat. No. 5,938,804, FIG.6 at 75; these two references being incorporated herein by reference.The types of radial seals depicted in those arrangements, could beadapted for use in a system as described herein, with appropriatemodification. One radial seal is shown in the alternate embodiment ofFIG. 20, discussed below.

The particular air cleaner assembly 2 depicted, however, uses apreferred axial seal between the primary filter cartridge 30 and theremainder of the air cleaner 2, to advantage. The term “axial” in thiscontext, is meant to refer to a seal which operates upon sealingpressure in the direction of arrow 68, FIG. 3, i.e., generally in adirection parallel to the element and housing central axis 12.

More specifically, and referring to FIG. 3, end 16 of housing sidewall 9is closed by end cover 18, with outlet 6 herein. Interior surface 69 ofend cover 18, around air flow exit aperture 69 a, is configured as asealing surface. That is, it is at this surface 69 that an axial seal isformed between the primary cartridge 30 and the housing 3.

Referring to FIGS. 5 and 6, end 57 of primary filter cartridge 30includes an end cap 57 a having circular ridge, projection or rib 70 ofseal material thereon, generally surrounding open central airflow exitaperture 71. Seal rib 70, FIG. 3, is pressed against surface 69,circumscribing aperture 69 a, to form the axial seal. The preferred rib70 has a somewhat triangular cross-section before the compression shownin FIG. 3.

The particular arrangement depicted in FIGS. 1-13, uses an advantageousarrangement to press the rib 70 against surface 69, forming the axialseal of the primary element 30. This is discussed in detail in SectionIV below, in which a detailed discussion of the primary filter cartridge30 is provided.

In general, because an inside radial seal of the type described in PCTPublication WO 89/01818 is not used in the preferred air cleanerassembly 2, housing 3 can be made free of any internally, axially,projecting radial seal tubes or cylindrical constructions, at end 16, ifdesired. Also, because primary filter cartridge 30 is free of any outerradial seals of the type described in U.S. Pat. No. 5,938,804 at 75, thehousing sidewall 9 for the preferred embodiment of FIG. 3 can be madefree of any otherwise necessary annular sealing surface for an outerperimeter radial seal.

III. Sealing of the Optional Safety Cartridge 31

Referring to FIG. 2, safety element or cartridge 31 includes first andsecond opposite ends, 80-81. First end 80 is the end inserted towardoutlet 6, during assembly. End 80 includes mounted adjacent thereto andspaced therefrom, o-Ring 84. Referring to FIG. 3, when mounted inassembly 2, end 80 is pushed into annular cylindrical projection 85 ofend cover 18 with o-Ring 84 providing a seal between the cartridge 31and an annular, inside surface of end 18, specifically section 18 c. Theseal provided by o-ring 84 ensures that an undesired level of air doesnot go through outlet 6 without passage through safety element cartridge31. It is noted that the seal provided by o-ring 84 is typically notcritical, since the seal of primary filter cartridge 30 primarilyprotects the engine from undesired (unfiltered) air flow.

The particular mechanism by which secondary or safety cartridge 31 issecured in position, and other features of secondary cartridge 31, aredescribed below in Section VI.

V. Primary Filter Cartridge 30

Attention is now directed to FIG. 6, in which primary filter cartridge30 is depicted in side elevational view. In general, the filtercartridge 30 comprises: a media and seal support structure 90; media 55;and, first and second opposite end caps 92 and 93. In general, end cap92 is positioned at end 57 of primary element 30; and, end cap 93 ispositioned at end 58. The media 55 extends completely between the endcaps 92, 93. For the particular embodiment shown support 90 also extendscompletely between the end caps 92, 93, although in some alternateembodiments, such extension might not be complete.

The particular preferred primary filter element or cartridge 30 depictedin FIG. 6, and generally used in air cleaner 2, does not have an innerfilter liner or support, extending completely between ends 57, 58,mounted as an inseparable part of cartridge 30. Rather, inner supportalong substantially the complete length of media 55 (except, forexample, at one or both of the potted ends), is provided, optionally, bystructure not mounted on and not provided as an inseparable part of, theprimary cartridge 30, as described below. It will be preferred that someinner support to the media is provided, either as part of cartridge 30or as a separate component, preferably as a separate component.

In general, end 57 is an open end, including aperture 71 therein forexit flow of air during a filtering operation. On the other hand, end 58is a closed end, meaning that air cannot pass through end 58 covered byend cap 93, during normal operation. Features which provide for this ina preferred manner will be understood from the following discussions.

The media and seal support structure 90 is depicted in FIG. 8. Thesupport structure 90 is shown in FIG. 8, without media or end capsthereon. Thus, support structure 90 depicted in FIG. 8 is a componentused to make cartridge 30, FIG. 6. In the cartridge 30, the supportstructure 90 is generally not separable or removable, without causingdamage to the cartridge 30.

From a review of FIGS. 1-3 and 8, it will be apparent that the preferredcartridge 30 is a “non-continuously threaded” cartridge. By this it ismeant that in the preferred embodiments there are no continuous threadson any portion of the cartridge 30, for threadably mounting, securing orattaching the cartridge (for example upon continuous rotation or through3600 or more of required rotation) to any portion of the air cleaner 2.

Referring to FIG. 8, the support structure 90 includes a first end 100and a second end 101. First end 100 generally defines a circular opening102 free of framework therein. The circular opening 102 (in thecompleted element 30 as aperture 71), provides for an exit region (oroutlet) for filtered air. In general, end cap 92 (FIG. 6), is moldedonto end 100 to provide closure to media 55 at this end. In a typicalpreferred embodiment, the end cap 92 also forms seal rib 70 and airoutlet aperture 71. Typically, to accomplish this, end cap 92 is formedfrom an appropriately compressible polymeric material, such as a foamedpolyurethane as described below.

Referring to FIG. 3, preferably seal rib 70 is positioned either axiallyaligned with edge 100 a of support 90, or is positioned radiallyinternally from overlap with edge 100 a. Typically it will be positionedradially inwardly from edge 100 a, with its peak no more than about 10mm. internally of edge 100 a. As a result, rib 70 is generally drivenagainst surface 69, to form a seal, by either end 100 a of support 90,or pleat ends of media 55, or both.

Referring to FIG. 8, support structure 90 includes, adjacent end 100,shield 105. Shield 105 is generally a portion of support structure 90which is imperforate or impermeable to air flow therethrough. The shield105 is generally sized, FIG. 3, to overlap aperture 7 a where dust droptube 7 encounters a remainder of sidewall 9. This inhibits dust, as itflows to the tube 7 a, from directly impinging the media 55 in anundesirable manner, in this region. Air can get under shield 105 at edge105 a, to encounter media 55 in this region (FIG. 3).

Attention is now directed to FIG. 6. In FIG. 6, in phantom, an optionalaxially projecting ring or rib 105 b is depicted. Such a ring 105 bwould be a continuous ring projecting axially outwardly, as itcircumscribes shield 105. Typically and preferably ring 105 b isintegral with a remainder of shield 105. The optional ring 105 b wouldpreferably be positioned adjacent to, but spaced from, portions ofmounting structure 129 described below, to inhibit undesired levels ofdust transport into that mounting structure 129. This will be describedin greater detail below.

For the particular embodiment shown, the support 90 extends completelybetween ends 100 and 101; and, between shield 105 and end 101, FIG. 8,support 90 includes a perforate or open section 106. By this it is meantthat in region 106, support 90 includes framework 107 that leavessubstantial open areas 108 for passage of air there through, toencounter media. Preferably in this region 106, the framework 107 is atleast 50% open, and more preferably at least 70% open. By this, it ismeant that of the total area of region 106, at least 50% and morepreferably at least 70% is occupied by aperture or opening, as opposedto solid framework. Preferably the imperforate shield 105 occupies atleast 10% but does not occupy more than 40% percent, of the totalextension (length) of support 90 between end 100 and end 101. Preferablythe perforate section 106 occupies at least 20%, more preferably atleast 60%, of a total axial length of support 90.

Still referring to FIG. 8, the preferred framework 107 depictedcomprises a plurality of radially spaced, axial ribs 109, in thisinstance 10 equally radially spaced such ribs, typically 6-14 such ribs,cross connected by a circumferentially, spiral, radial rib structure 109a, in this instance two continuous spirals 109 b extending fromapproximately points 109 c (separated radially by about 180°) adjacentend 101, to points 109 d (separated radially by about 180°) adjacentshield 105, each with a total radial extension of about 720°. Advantagesfrom a spiral rib structure 109 a, as opposed to a series of parallelradial ribs, relate to provision of resistance to distortion offramework 107 when placed under radial stress during sealing anunsealing of cartridge 30. An alternate way to describe the spiral turnof radial ribs 109, is that they angle, from being perpendicular tocentral axis 12, FIG. 3, by at least about 10°, and typically an anglewithin the range of 15° to 45°. This can alternatively be stated to bethe acute angle B, FIG. 6.

Attention is now directed toward end 101, FIG. 8. In general, end 101includes end framework 110 extending there across, in contrast toopening 102 at end 100. Framework 110 does not completely close end 101,but rather includes the following general features: central, impermeableregion 111; and, annular open framework 112.

Still referring to FIG. 8, annular open framework 112 generally includesspokes 113 (in this instance 8 spokes, typically 3-11 spokes) extendingbetween impermeable region 111 and end 101; and, structural, circular,rib 114 interconnecting the spokes 113. Openings 115 defined bystructure 112, help provide for preferred manufacture of primary element30, as next described.

During a preferred manufacture of primary element 30, a pre-made, moldedplastic, component comprising support 90 would be provided. Pleatedmedia would be put into support 90, through opening 102. The pleatedmedia would be inserted sufficiently far, for an end of the media torest upon framework 112. Recessed surface 111 a in region 111 projectswith the media around it, toward end 102 to define an annular mediareceiving trough 116 therearound, to help keep the inserted end of themedia in a round shape.

End 101 of the framework 90 could then be placed into a mold, includinga curable polymeric material. The polymeric material will flow throughthe framework 112, into the ends of the media pleats, to form a potting,as shown at end cap 93, FIG. 6. This will seal ends of the pleatsclosed, secure the media in place, and close openings 115. In general,the potting material and mold depth will have been selected so as to notto have the potting material reach surface 111 a of recessed region 111.A typical depth of recess for surface 111 a from end 101 would be atleast about 3 mm. and usually not more than 7 mm., for example 4-5 mm.

Attention is directed to FIG. 4, in which an end cap 93 formed by such aprocess is depicted. The potting material is generally indicated at 120.It can be seen that although region 111 has not been covered by thepotting material 120, the remaining framework 112 has been. For theparticular arrangements shown in FIG. 4, the molded potting material 120is shown with annular, radially spaced, depressions 121 resulting frommold standoffs.

End cap 93, then, is a composite, closed, end cap 58, with the compositegenerally comprising: potting material 120 forming an annular,imperforate, ring; and, exposed surface 111 which forms a centralimperforate surface in the end cap 93.

Manufacture of the element 30 could be completed, by inserting end 100into a second mold, and molding end cap 92 thereon. The media 55 wouldbe prevented from dropping through aperture 102, during insertion intothe second mold, since it would have been anchored in place to framework112 by the first molding process.

The primary filter cartridge 30 of the preferred embodiment includesthereon structure to provide for securement of the cartridge 30 in placeand assembly 2, during use. For the particular preferred constructionillustrated, the mounting structure is provided as an integral part ofsupport 90; however alternatives are possible. The structure can beunderstood, in part, by review of the support 90, FIG. 8.

In FIG. 8, mounting structure 129 providing for securing cartridge 30with seal material 70, (FIG. 3) compressed against surface 69, FIG. 3,is depicted. The particular mounting structure 129 depicted, is part ofa non-continuously threaded, rotation engagement mechanism 129 a, whichis operated to press seal material 70 against surface 69 in part upon arotational moment imparted filter cartridge 30. It is this operation ofproviding radial twist to the cartridge 30, during locking and mounting,which is facilitated by providing support 90 with spiral construction109 a. The preferred arrangement shown is configured so that arotational motion of no more than 50°, preferably no more than 30°, mostpreferably 20° or less, is all that is necessary to go from an unlockedposition to a locked position. This will be apparent from the followingdescriptions.

The engagement structure 129 a in general operates with a portion ofcartridge 30 engaging, upon rotation, a portion on the housing section25. An example of a particular interaction will be understood byreviewing FIG. 8, specifically radially outwardly projecting ring 130,which operates as mounting structure 129 on cartridge 30.

Radially projecting ring 130, in the embodiment shown, is a segmentedring 131. The particular embodiment shown comprises four identical,evenly spaced, segments 131 a; however alternatives are possible. InFIG. 5, three of the segments 132, 133 and 134 are viewable. The fourthsegment 135 would be positioned as shown in FIG. 5. All four areviewable in FIG. 7. Each segment 131 a projects radially outwardly, froman immediately adjacent portion of support 90, by at least 2.5 mm.,typically at least 3.5 mm.

Referring to FIG. 8, segmented ring 131, has a series of radially spacedgaps 136 therein. The gaps 136 are positioned between the segments132-135 of the segmented ring 131. The gaps 136 are appropriately sizedto allow at least selected portions of ring 131 to be pushed (axially)past structural features in the housing 9, for rotational engagement asdiscussed below. Each gap 136 is preferably at least 6 mm. wide,typically at least 7 mm. wide. Gaps on the order of 20 mm.-40 mm. areuseable, for example.

Referring to FIG. 8, each ring segment 131 a (such as segment 133),includes first and second opposite ends 140 and 141. End 141 istypically a blunt end; and, end 140 comprises a short segment at 142axially offset (from a remainder 143 of the segment 131) toward end 100.A result is formation of a receiving area 145 along a surface 146 ofsegment 142 facing toward end 101 (or away from end 100). Receiving area145 is positioned to engage (upon radial receipt) structure in thehousing 9, discussed below, to ensure appropriate sealing between theprimary element 30 and the housing 9, during operation. It is noted thattip 147 of section 140 comes to a rounded point, with surface 145 beinga cam surface and recessing from tip 147 toward end 101 in extensiontoward section 143. It is also noted that each of the ring segments132-135 is oriented with its offset section corresponding to section142, FIG. 8, on one side of a gap 136, and with a blunt end,corresponding to end 141 of the next adjacent ring segment, positionedon the other side of the corresponding gap 136. In the instance shown,and from the end view from end 101, each segment 131 “points” inclockwise arc, with end 141 being considered the front end.

Attention is now directed to FIG. 10. In FIG. 10 a cross-sectional viewof portion 25 of the housing 9 is depicted. In FIG. 10, holder structure150 is shown. From FIGS. 9 and 10, it will be apparent that for theparticular embodiment shown there are four, evenly spaced, holderstructures 150, one corresponding to each gap 136, in ring 130.

Each holder structure 150 is positioned adjacent an inside surface 41 ofhousing 9 at region adjacent section 18 b (at a joint area betweensections 18 a and 18 b) of the housing sidewall 9. Each holder structure150 is sized to pass through a gap 136, FIG. 8; further, surface 151,which is directed toward outlet 6, is shaped as a cam to slant towardoutlet 6 in recess from tip 150 a. Finally, holder 150 includes end stop152 thereon at an end opposite tip 150 a.

From the viewpoint of FIG. 9, i.e., looking toward end 17, each of theholders “points” counter-clockwise, if it is assumed that the tip 150 ais the front of each holder and that the stop 152 is the back end.Pointing this direction facilitates engagement with ring segment 131,which, as characterized above, points in an opposite direction. It isnoted that if the ring segments 131 are configured to pointcounter-clockwise, then the holders 150 could be directed to pointclockwise. (These and other alternative arrangements will be understoodfrom the following description of operation.)

Although alternatives are possible, in the particular embodiment shown,the housing 3 would include four holders corresponding to holder 150,evenly radially spaced around an interior of surface section 18 b, eachpointing in the same direction. Again, the four holders 150 wouldgenerally correspond with the four gaps 136 between the four ringsegments, 132-135.

Operational engagement between the primary filter cartridge 30 and thehousing 3, to cause sealing between gasket 70 and surface 69 should nowbe apparent. In general, cartridge 30 would be inserted into the openhousing 25 through open end 17, FIG. 10. The end of the element 30inserted first, would be end 57 FIG. 6. The cartridge 30 would continueto be pushed in, with an appropriate radial orientation such thatholders 150 can pass through gaps 136. This will allow gasket 70 toencounter and be pressed against surface 69, FIGS. 3 and 10. Once thisextent of insertion is reached, the cartridge 30 would be rotated, (forthe particular embodiment depicted clockwise), so that portions 142 ofeach ring segment would be aligned over surface 151 of each holder 150.The surface 145 of each section 142 and surface 151 of each holder 150,i.e., the engaging surfaces, would be shaped and sized to cause afurther biasing or camming to drive cartridge 30 against surface 69preferably with compression of rib 70, to ensure appropriate compressionof the gasket material 70 to form a seal. Rotation would preferably bedesigned to occur until tip 147 engages stop 152.

As a result of the rotational interlock, the cartridge 30 cannot backaway from surface 69 without being rotated, due to the holders 150 beingpositioned against surfaces 146.

Referring to FIG. 10, in general the arc length between tip 150 a andstop 152, represents the rotational arc between full locking and fullyunlocking of the cartridge 30. Typically, the construction will be suchthat the arc is no more than 70°, typically no more than 50°, and forthe particular embodiment of FIG. 10, preferably no more than 40°. Mostpreferably, for the embodiment of FIG. 10, it is no more than 30°.Indeed, for the particular arrangement shown, this arc is on the orderof only about 10° to 25°.

From the above, it will be apparent for the particular preferredembodiment shown, the primary filter cartridge 30 includes no innersupport structure extending between ends 57, 58, along an inside surfaceof the media 55. This is advantageous, for manufacture and assembly.When the cartridge 30 is positioned for use, in an air cleaner, innersupport to the media 55 is provided by structure already positionedwithin the housing 3.

More specifically, internal support for the media 55 is provided by aseparate support structure 160, FIG. 2 for example a portion of thesecondary or safety element or cartridge 31. In the event that anoptional secondary or safety element 31 is not used with the system, asupport structure similar to structure 160, but not having mediaassociated therewith as a secondary filter, can be used to support media55 along its inside.

Attention is again directed to the optional rib 105 b shown in FIG. 6.Such a rib 105 b, in use, would generally be positioned spaced axiallytoward end 93 from mounting structure 129, specifically axially towardend 93 from segment and ring 131. Preferably the spacing the optionalrib 105 b from the segmented ring 131, in this direction, would be by nomore than 10 mm., and preferably substantially less. The continuous ring105 b would generally protect segmented ring 131 from being undesirablyexposed to dust, during use.

In some alternate embodiments, it may be desirable to have framework 90not extend continuously from end 100 to end 101; but rather to have thesupport 90 include shield 105, without framework from end 101; and, tohave at opposite end 101 appropriate structure (such as impermeableregion 111 and annual open framework 112), for forming a preferredcomposite end cap.

V. The End Cover 20

As indicated previously, the end cover 20 is a service cover 21 that canbe removed from the remainder of the housing 25 to allow service accessto the interior 23 of the housing.

For the particular embodiment shown, the end cover 20 has no air flowaperture extending therethrough. That is, it has an outside surface 20a, FIG. 1 and an inside center surface 20 b, FIG. 5, with no aperture orair flow tube extending therethrough. For this reason, it can bereferred to as a “closed” or “completely closed” end cover 20.

Referring to FIGS. 1, 2 and 4, assembly 2 includes a mounting andlocking mechanism 170, to secure the cover 21 onto the remainder 25 ofthe housing sidewall 9. In general the mounting and locking mechanism170 comprises a plurality of flexible tabs mounted on one of the housingsidewall 9 and cover 20, and a plurality of engageable recesses mountedon the other one of the housing sidewall 9 and cover 20. For theparticular arrangement shown, the mounting and locking mechanism 170generally comprises a plurality of flexible tabs 171, on end cover 21,each of which includes a radially projecting tongue 172, FIG. 4,thereon. For the particular embodiment shown, the mounting mechanism 170comprises two tabs 171 a, 171 b, radially spaced 180° apart, around thecircumference of cover 21. The housing and 17 includes a pair ofrecesses or slots 175, FIG. 1, therein, for receipt of tongues 172, whenthe service cover 21 is mounted.

Operation, then, is as follows: referring to FIG. 1, in order to removeservice cover 21 from the remainder of housing 3, tabs 171 would bebiased toward one another. This would move the projecting tongues 172(FIG. 4) out of slots 175, releasing the cover 21 for movement relativeto the housing sidewall 9. Insertion would be a reverse operation.Particular useable materials for formation of the cover 21, to provideflexible tabs 171, are discussed below. If the tongues 172 are providedwith appropriately cammed surfaces on an end directed toward remainder25 of the housing, when the cover 20 is pressed in place, it will not benecessary to bias the tabs 171 by hand during mounting, but rather thecams would cause the biasing or snap fit mounting as the cover 20 ispressed in place.

An advantage to the particular mounting and locking mechanism 170described, it is that it comprises features integral with cover 20 andhousing 9, and does not require the attachment of any additionalmechanisms such as latches, hooks, etc., for operation, after cover 20is molded.

For the particular mounting system involved, only two tabs 171 and slots175 are used; and, each tab 171 can engage each one of slots 175. As aresult, as thus far described the cover 21 could be mounted in tworotational orientations relative to sidewall 9. However, if this werepossible for the particular embodiment depicted, the cover 20 could bemounted such that the orientation between the inlet 5 and the ramp 36 isnot appropriate. To ensure that the cover 20 is only mountable in asingle rotational position, relative to a remainder of the housing 25,an indexing arrangement can be provided. Specifically a slot and keyarrangement can be used, in which one member (slot or key) is positionedon the cover; and another member (key or slot) is on the housingsidewall 9. The two members would be positioned so that the cover canonly fit (slot engage key) when it is rotated to a specific pre-setorientation.

An example as illustrated in the embodiment of FIG. 15, in which a cover700 is shown mounted on a sidewall 701, with a key or pin 702 on thecover 100 received within a slot 703 on the sidewall 701. Cover 700could only be properly mounted, if the key or pin 702 is aligned withthe slot 703. Thus, the slot and key arrangement 705 depicted in FIG. 15ensures that the cover 700 is appropriately rotationally mountedrelative to the housing sidewall 701, for proper operation.

Referring again to FIG. 1, an optional handle construction 710 is shown,in phantom, on cover 20. If desired, the tabs 171 and slots 175 could beconfigured such that under a hand (pulling) force applied to handle 710,(i.e., under pulling of the handle 710), the cover 20 could be releasedfrom its secure position without the need to manually press tabs 171toward one another. The handle 710 could be configured in a variety offorms. The particular handle 710 shown includes a removable orreplaceable cross piece 711 extending between two mounting ears 712,713. The ears 712, 713 could be molded integrally with a remainder ofcover 20.

Attention is now directed to FIG. 5, for detail within shield 37 oncover 20. In particular, in a portion 178 inside of shield 37 which willbe adjacent end 58 in use, cover 20 includes an internal ring 179 ofsmaller inside diameter than a remainder 179 a of shield 37. The ring179 a, FIG. 3, is sized to receive end 58 therein with little or nospace therebetween in use. This will help securely support the end 58 ofprimary cartridge 30, along end cap 93, i.e., at an end of cartridge 30remote from outlet 6.

Referring to FIG. 6, the primary filter cartridge 30 is supported at end57, within the housing 3 (FIG. 3), by a combination of: the mountingstructure 129; and, end cap 92.

Referring to FIG. 4, attention is now directed to an engagementarrangement, for providing a preferred engagement between primaryelement 30 and cover 20. In particular, and referring to FIG. 4,impermeable region 111, in primary filter cartridge 30, includesrecessed surface 111 a in the pre-form comprising a portion of framework90, and includes centrally positioned in surface 111 a, a first member183 of a projection/receiver arrangement 184. In particular, surface 111a includes receiver 185. Preferably, the receiver 185 is non-circular,for reasons discussed below. The particular receiver 185 depicted forthe embodiment shown in FIG. 4, is an X-shaped (or “+” shaped) receiver186 with a 90° angle between center lines of each pair of adjacent armsof the X-shape, although a variety of alternate shapes can be used. Aparticular advantage resulting from the X-shape to the receiver 186, isdiscussed below with respect to indexing and symmetry. The term“pre-form” in the context of this paragraph, refers to a structuralcomponent of the end cap made prior to potting into the end capmaterial.

Further, as shown at FIG. 5, cover 20 includes, along the inside surface190 thereof, a second member 187 of the projection/receiver arrangement184, in this instance a centrally positioned projection 191. Again,preferably projection 191 is non-round and in this instance is anX-shaped projection 192, with a 90° angle between a center line of eachpair of adjacent arms of the X-shape. The projection 192 is sized andconfigured to project, when appropriately aligned, into receiver 185.When the air cleaner 2 is assembled, FIG. 3, projection 191 willprotrude into receiver 185. In part because the projection 192 andreceiver 186 are both non-round, the cartridge 30 is prevented fromrotating, in use, by the projection/receiver arrangement 184, when theair cleaner end cover 20 is locked in position on housing 3.

In particular, it is important that during use, the element 30 notinadvertently rotate relative to the housing 3, to ensure that the sealbetween gasket material 70 and surface 69 is maintained. That is,relative rotation between element 30 and surface 69 would tend todisengage the interaction between holders 150 and ring segments 131. Toinhibit rotational movement of the element 30 relative to the remainderof the housing 3, during assembly and use, projection 191 and receiver185 are shaped, to engage upon rotation and inhibit a sufficientrelative rotational movement between the cartridge 30 and a remainder ofair cleaner 25, to allow the cartridge to unseal. The particular shapeshown for each is an X-shape. However, with respect to this generalfunction, all that is generally required is that the projection 191 andthe receiver 185 not be circular, but rather each be non-circular andhave a portion that interacts with the other and inhibits rotationalmovement of one relative to the other.

The particular use of a four armed cross or X-shape (or +-shape; i.e.,“plus shape”) for each member, relates to an indexing and symmetryfunction. In particular, ring 131 of primary filter cartridge 30includes a specific number (N) of radially spaced gaps 136. As a resultof this configuration, and also the same number (N) of holders 150 andthe same number (N) of segments 131, cartridge 30 can be positionedwithin housing 3, at N specific radial orientations. When N is thenumber 4, and the four positions are 90° apart, each one of these Nradial orientations corresponds to an arm 193 of projection 191. Sincethere are a total of four gaps 136, four holders 150 and four sections131, the particular projection 191 depicted is an X-shape 192 with fourarms 193 each extending at 90° relative to adjacent arms. Of course,receiver 185, FIG. 4, is similarly constructed. Thus, the element can bemounted in four rotational positions.

Such a symmetry between a number of possible rotational positions andengagements, between the primary cartridge 30 and the remainder of thehousing 3, will generally be referred to as a primary cartridge/housingrotational symmetry. For the particular embodiment shown, the primarycartridge/housing rotational symmetry is four fold, meaning fourrotational orientations, but not more, are possible. Of course,alternatives are possible; however, preferably at least two possiblerotational positions are provided.

The extent to which the projection member 191 extends into the recess orreceiver 185 (of the preform), of the projection/receiver interlockarrangement 184, is not critical, as long as the extent of projection isenough to inhibit rotation. It is anticipated that in generalconstructions will be made such that the amount of projection into thereceiver 185 from surface 111 a will be at least 3 mm., typically atleast 5 mm., and generally on the order of 6 mm. to 10 mm.

Of course the first member of the projection receiver arrangement 183,could be a projection as opposed to a receiver, with the second memberbeing the receiver instead of the projection. That is, theprojection/receiver arrangement 184 could be configured with aprojection extending axially outwardly from surface 111 a, toward cover20, to be received within a receiver on end cover 20. The particulararrangement depicted, however, with receiver 185 on the cartridge 30,and the projection 191 on the cover 20, is preferred.

Again, it is noted that impermeable end 111 and framework 112 (FIG. 8)are preferably formed as a pre-form, before a remainder of end cap 93,FIG. 6, is molded.

Referring to FIG. 3, it is also noted that the preferred cover 20 iscircumscribed by end 17 of housing sidewall 9, when the cover 20 isproperly mounted; and, the cover 20 includes no portion which slidesover (or around) region 17 a on an outside surface of end 17 of sidewall9. A cover 20 configured in this manner, will sometimes be referred toby the following characterizations: “cover 20 is positionedcircumscribed by a portion of housing 9, when mounted, and cover 20includes no portion which circumscribes housing 9, when mounted,” or byvariants thereof. Alternative arrangements for mounting the cover 20,are described below.

VI. The Optional Safety Element 31

Attention is directed to FIGS. 11-13, with respect to the optionalsafety element 31. In general the safety element 31, FIG. 13, comprises:support 160; inner support 201; media 65; and, o-ring 84. The support160 generally extends between first end 80 and second end 81. The firstend 80 is the end first inserted into the housing interior 23, duringmounting. End 80 includes o-ring 84 mounted spaced therefrom butadjacent thereto, and positioned in o-ring receiver 203. For theparticular embodiment shown, end 80 includes, immediately adjacentthereto, impermeable ring surface 205 with mounting slots 206 therein.The mounting slots 206 are generally L-shaped (or J or hook shaped),FIG. 12, and are positioned to engage posts 210 within housing 3, FIG.9, upon an appropriate engagement and twist. The posts 210 projectradially inwardly. (An alternate embodiment is described below whichdoes not use a slot 206/post 210 engagement mechanism.)

For the particular arrangement shown in FIGS. 11-13, there are two slots206 and two posts 210, each member of each pair being positioned rotated180° from the other around an inside of housing 3. The posts 210 are onsurface 18 c. Thus, outer support 160 is configured to have tworotational positions relative to the housing 3, during installation. Thesymmetry between support 160 and the housing 3 will generally bereferred to as support 160/housing symmetry or by variants thereof.Symmetry with two possible positions, but not more, will be referred toas two-fold support 160/housing symmetry.

Referring again to FIG. 13, support 160 comprises framework 211 withapertures 212 therein. Preferably support 160 is at least 50% open andmore preferably at least 70% open, in extension between end 80 and end81. In general use, safety cartridge 31 does not have a substantialtwisting and pressure applied thereto, simply to operate interactionbetween slots 206 and posts 210. That is, the rotation to operateinteraction between posts 210 and slots 206 is relatively easy. Thus,the support framework 211 does not have spiral radial extensions, butrather uses parallel hoops 213 (in this instance five hoops)interconnecting axial extensions 214.

End 80 generally defines an open circular interior 80 a, through whichair can pass during use. End 81, on the other hand, is closed by cover215. For the particular embodiment shown, cover 215 includes a recessedcenter 216, configured as described below.

For the particular safety element depicted in FIGS. 11-13, the media 65comprises a wrap or similar construction of non-pleated, non-woven,material. It is positioned generally between inner support 201 andsupport 160. Referring to FIG. 13, the inner support 201 is generallyframework having first and second opposite ends 222, 223, with an openor porous support structure 229 extending therebetween. Preferably theporous structure 229 is at least 50% open and more preferably at least70% open, over this extension. For the particular embodiment shown thesupport structure 229 is a series of radially spaced axial extensions229 a supported by parallel, spaced, hoops 229 b, in this instance fivehoops, not counting end 229 c.

For the particular embodiment shown, end 222 of inner support 201defines an open circular opening 222 a, for passage of air therethroughduring use; whereas end 223 is closed by end cover 225. The preferredend cover 225 depicted, includes a recessed center portion 226.

The particular components 160, 201 depicted in FIG. 13, are configuredfor engagement. In particular, media 65 can be positioned around anouter surface 201 a of inner support 201. This assembly could then beprojected into an interior 160 a of support 160, until end cover 225engages end cover 215, FIG. 12.

For the particular arrangement shown, cover 215 includes a pair ofapertures 230 therein, sized and shaped to receive posts 231, on cover225, for an interlocking engagement. Interference (snap) fit, heatstaking or other construction methods can alternatively be used.Preferably in the immediate area where the components 160, 701 directlyengage for interlock, there is no media 65 positioned between them.

It is noted that cover 215 is sized and recessed for a telescoping fitor projecting fit, into a recess 225 a defined by cover 225. This, inpart, accommodates recess 216 a in support 60 which in turn accommodatesthe projection/receiver arrangement 184, when air cleaner 2 isassembled, FIG. 3.

Attention is still directed to FIG. 3, with respect to completeassembly. It is noted that recess 185 of the primary filter cartridge 30projects (in the preferred embodiment shown) partially into recess 216 adefined by the cover 215. As a result, each of the primary element 30and the safety element 31 are inhibited from coming loose and moving ina direction toward cover 20, during assembly and use.

In those instances in which it is desirable not to utilize optionalsecondary or safety filter 31, it may be desirable simply to installsupport 160 with no media 65 or support 201 associated therewith, intohousing 3. The support 160 would still operate, then, as inner supportfor the primary filter cartridge 30.

In general, the apertures 230 and posts 231, FIG. 13, can be viewed as aprojection/receiver arrangement 233, FIG. 12, for the safety elementcartridge 31. The projection/receiver arrangement 233 could beconfigured, alternatively, with the projection on the outer support 160received within receivers on the inner support 201, or in furtheralternate arrangements, if desired. In general terms, then, the innersupport 160 includes a first member of projection/receiver arrangement233, and the inner support 201 includes a second member of such anarrangement.

IX. The Outer Surface Shape of the Components 30, 31

Referring to FIG. 6, it is noted that the primary element 30 has anouter surface shape, which is generally conical. More specifically,region 240, FIG. 6, of outer support 90 is a wide end and has a firstdiameter D1, and region 241 is a narrow end and has second diameter D2with:

-   -   (a) D1 greater than D2; and    -   (b) a dimensional decrease in cross-sectional diameter being        generally even in extension between points 240 and 241.

Typically and preferably diameter D1, a largest diameter adjacent end57, is at least 10% larger than diameter D2, a diameter adjacent asmallest end 58. Typically and preferably the diameter D1 is at least 10mm. larger than the diameter D2. Such a shape may sometimes be referredto as frusto-conical, since the conical shape does not taper to a point.

This generally conical shape, which includes shield region 105 and openregion 106, provides for advantage. First, the narrow end at 241, allowsfor an outside diameter that accommodates some of the space taken by theramp 36 and shield 37 of the precleaner 35, without a larger diameterbeing needed for air cleaner housing sidewall 9. On the other hand, thelarger diameter D1 at region 240 allows for a relatively large exitaperture 102 and thus reduction in restriction to exit air flow whilemaintaining a relatively large amount of media 55. Also, referring toFIG. 3, the increase in diameter of shield section 105 in extensionbetween points 242 and 243, helps direct dust or other particles intoaperture 7 a of down tube 7.

In general, referring to FIG. 12, the particular preferred safety filtercartridge 31 depicted has an analogous conical shape with a diameter D3at region 250 greater than diameter D4 at region 251 and an even taperand decrease in diameter therebetween. This will ensure that supportmember 160 of the safety filter cartridge 31 is positioned adjacentinternal pleat tips of media 55 in cartridge 30, for support therealong.

X. Jointed Housing Construction

Attention is directed to FIG. 1. In particular, the housing 3 depictedhas a sidewall 9 which is a segmented sidewall 260. By “segmented” inthis context, it is meant that the sidewall 9 includes at least twosections 261, 262 which are not formed integrally with one another, in asingle molding, but rather which are separately made and aremechanically secured along a joint or seam 263, to form sidewall 9.

For the particular embodiment shown, the segmented housing 260 includes,in first section 261, the following: end 16; outlet tube 6; and, downtube 7. In segment 262, the housing 260 includes: inlet tube 5; and, end17 for mounting cover 20.

Engagement between segments 261 and 262, at joint 263, is providedthrough an interlock mechanism 270. In general the interlock mechanism270 includes a plurality of projections 271; and, a plurality ofreceivers 272, in this instance flexible latches or unshaped hoops 273.The hoops 273 are sized to snugly snap fit over the posts 271, whensection 262 is pressed toward section 261. For the particular embodimentshown, each of the posts or projections 271 is generally rectangularlyshaped and each of the latches or hoops 273 has a similarly shapedaperture therein, to facilitate snug fit.

For the particular embodiment shown, the projections 271 are evenlyradially spaced around outer surface 272 of segment 261; and, theflexible latches or hoops 273 are evenly radially spaced around outersurface 274 of section 262. Alternate constructions are of coursepossible. For example, the specific locations could be reversed. Theparticular embodiment shown, however, is preferred.

For the arrangement shown, the central aperture of each latch or hoop273 has a perimeter size of about 12 mm. wide, with the post orprojections 271 having a similar width. Each post 271 has a length ofabout 11 mm., with a cam shape from tip 271 a to sharp edge 271 b, FIG.10.

Referring to FIG. 1, for the particular arrangement depicted, section261 includes an enlarged (in diameter) rim section 280 adjacent end 281,to receive a portion of surface 274 therein, and to circumscribe thatportion, during assembly. This is also shown in FIG. 10.

In a preferred embodiment, at least six radially spaced posts 271, andsix radially spaced latches 273, are used. Typically and preferably thenumber of each will be about eight to fourteen.

Advantages from the segmented housing construction will be understood byreference to FIG. 1. In particular, segment 261 will be mounted ororiented, on a vehicle, such that drop tube 7 is pointed generallydownwardly. This facilitates operation of dust evacuation throughevacuator valve 32.

The inlet tube 5 will generally need to be directed, for variousequipment, toward a preferred location for an inlet tube to beconnected. For different vehicles, it may be desirable to have adifferent orientation (radially) between the center line 11 or directionof tube 5, and tube 7 from that shown in FIG. 1. The segmented housingallows for section 262 to be mounted on section 261, in at least 2 andpreferably more selected rotational orientations.

The particular segmented housing 260 depicted in FIG. 1, is organized topermit four possible rotational orientations, each 90° spaced from oneanother. Indexing between the four arrangements is provided by indexingarrangement 290. In general, the indexing arrangement 290 comprises arib/detent arrangement in which ribs are used in one member of the twohousing pieces, and detents are used on another member of the twohousing pieces, to index line for joining.

The indexing arrangement 290 for the arrangement shown, comprises fourribs 291 which extend axially and project radially outwardly fromsurface 274, each of which engage an associated detent or receiver 292in section 272 of segment 261. Four evenly spaced interference fittingribs and detents, index four possible rotational orientations of thesegment 262 relative to segment 261, for sliding engagement andactivation of the snap fit locking mechanism 270.

In general, the snap fit locking mechanism 270 should be selected so asto make disconnection relatively difficult. This is because it is notanticipated that, typically, once assembled and installed, air cleaner 2would be reconfigured for a different rotational relationship betweensegment 262 and segment 261.

Another possibility allowed or accommodated by a segmented housing 260,is having a single mold for segment 261, while having alternate moldsfor segment 262, for example to vary overall housing axial length or toaccommodate, in a custom manner, a different cartridge 30.

Of course the segmented housing is optional. In FIG. 14, there isdepicted a housing 300 which is not segmented. The housing 300 may be inaccord with the description given about for FIGS. 1-13, except for theabsence of the segmented housing.

XI. Selected Alternate Embodiments A. An Alternate Mounting Approach forthe Safety Element, FIGS. 16-19

For the embodiment of FIGS. 1-13, the safety element 31 was mounted by atwist mount involving interaction between slots 206 and posts 210. Analternate arrangement is shown, in FIGS. 16-18.

In FIG. 16, an end view in air cleaner 400 according to the alternateembodiment is shown. The end view of FIG. 16 is generally analogous tothe end view of FIG. 9. The parts used in air cleaner assembly 400 maybe generally as described above the embodiment of FIGS. 1-13, or even ascharacterized in alternate embodiments, except as described herein inconnection with the mounting of the safety element.

In general, the air cleaner assembly 400 includes a housing 401 havingan outer sidewall 402. In FIG. 16, the air cleaner assembly 400 is shownwith an end cover removed. However, the end cover may be generallyanalogous to end cover 20, FIG. 1.

Attention is now directed to FIG. 17, which is a cross-section takenalong line 17-17, FIG. 16. Referring to FIG. 17, the sidewall 402 is ajointed sidewall having segments 405 and 406. The segments 405 and 406may be generally as described above in connection with segments 261,262, FIG. 1. It is noted that end 410 of the sidewall 402 is closed by astepped cover 411 having outlet 412 projecting therefrom. The outlet 412includes a tap 413 for a pressure sensor or similar arrangement.

More specifically, cover 411 is stepped at first step 415 and secondstep 416. In use, the safety element is sealed to second step 416.

Unlike the arrangement of FIGS. 1-13, there are no posts positioned inthe step 416, for securing a safety element in place. Rather adjacentregion 416, immediately between step 416 and 415, are provided severalspace protrusions 420. For the arrangement shown, there would be fourprotrusions 420, equally radially spaced around an inner most edge ofstep 416. The operation of these protrusions 420 will be understood fromfurther description below.

Attention is now directed to FIG. 18 which depicts a fragmentary view ofa portion of the housing 401 depicted in FIG. 17, but with the safetyelement 430 mounted therein. The safety element 430 maybe generally ascharacterized above for safety element 31, except for mounting mechanismthereon, described herein. In particular, safety element 430 does notinclude any slots analogous to slots 206. Rather safety element 430 onlyincludes an o-ring receiver 431 with 432 therein.

During assembly, safety element 430 would be pressed toward step 416 inthe general direction of arrow 440, as the safety element is insertedinto open end 445, FIG. 17, of the housing 401. The safety element wouldcontinued to be pushed in the direction of arrow 440 until the o-ring432 is sealed against an inner surface 416 a of step 416. In order toaccomplish this sealing, the o-ring 32 would need to be pushed passedprotrusions 420. The protrusions, then, will act to cause aninterference fit, prohibiting the likelihood that the safety element 430would not intentionally become dislodged from its mounting, FIG. 18, bymovement of the safety element in the direction of arrow 450. Theprotrusions 420, then, in combination with the outside diameter of theo-ring 43, causes a lock fit of the safety element 430 in place, withoutrequiring a twist motion.

Of course the mounting approach described with respect to FIG. 16-18could be applied with a non-jointed housing, if desired.

B. A First Alternate Cover Mount

An alternate cover mount is shown in FIG. 19. Referring to FIG. 19 aircleaner assembly 500 is depicted, comprising a housing 501, having anouter sidewall 502 and a cover 503 mounted thereon. Except for theapproach of mounting, the cover 503 may be generally similar to cover20, FIG. 1, including options described.

In particular, cover 503 is mounted onto end 505 of housing sidewall502, by over center wire latches 506. This is opposed to using a latchmechanism such as the integral latch mechanism described for theembodiment of FIGS. 1-13.

It is noted that the arrangement of FIG. 19 includes a pin or key 530positioned on the cover, to be received within a slot 531 at end 505 ofsidewall 502, to ensure appropriate radial orientation of cover 503relative to sidewall 502 during mounting. That is, cover 503 for thearrangement shown, can be mounted in only one radial orientation.

C. An Alternate Mounting Arrangement for the Primary Element, FIG. 20

In the embodiment of FIGS. 1-13, the primary element 30, is mountedusing a rotation lock mechanism 129, as described. As a result, theprimary element 30, is sealed with an axial seal as described.

An alternate approach, which utilizes a radial seal mechanism, ispossible, as previously indicated. One such arrangement is shown in FIG.20.

Referring to FIG. 20, a fragmentary perspective view of an alternateprimary element 600, is shown. In FIG. 20, the portion of the element600 viewable, is the end cap 601 that would correspond to the end capthat is inserted furthest into the housing, during use. In particular,end cap 601 is the exit end for filtered air.

End cap 601 is provided with a central axial protrusion 602 thereon,that projects axially away from a remainder 603 of the primary element600. The axial protrusion 602 includes an o-ring mount 605 with ano-ring 606 positioned thereon. With such an arrangement, the primaryelement 600 could be mounted by insertion past the protrusions 420, FIG.18, in place of the safety element. That is, primary element 600 couldbe mounted analogously to safety element 430, FIG. 18. That result wouldbe a radial seal formed by o-ring 606, as opposed to an axial sealarrangement.

During normal mounting, the filter element 600 of FIG. 20, would not betwisted or rotated. Thus it may be preferable to manufacture primaryelement 600 without outside framework extending completely between theopposite ends. Rather, while shields may be at positions adjacent eachend (or at least the outlet end) to facilitate use, it may be desirableto leave cross hatch open framework extending between the ends out,since it would not be needed to translate rotational motion and providefor support. This is a matter of choice, depending upon other featuresin the construction.

A safety element could be mounted in association with arrangement suchas FIG. 20, by providing a structural location in region 610, to allowfor the safety element to be mounted. It is noted that for theparticular arrangement of FIG. 20, internal (optional) open framework612 is shown extending axially along inside 613 of the element 600. Theopen framework 612 could extend from end to end, of the element 600.

D. An Alternate Primary Element with a Precleaner Mounted DirectlyThereon

For the embodiment of FIGS. 1-13, the precleaner 35 was mounted directlyon the cover 20. As indicated previously, alternate embodiments areshown. In particular, attention is directed to FIG. 21, in which aprimary filter element 800 is depicted, in fragmentary, cross-sectionalview. In particular, a closed end 801 of the primary filter element 800is depicted. Closed end 801 is shown having framework 802 extendingthere across, with the receiver 803, for engagement with the cover. Theframework 802 is shown secured in place by end potting 805. This closesthe end of media 806. As thus far described, the arrangement isgenerally analogous to the primary element 30 of FIGS. 1-13. However,for element 801, shield 810 and ramp 813 are shown non-permanently aspart of the primary filter element 800, thus are not mounted on thecover. FIG. 21 is presented simply to indicate an alternate arrangementin which a precleaner 815, comprising of shield 810 and ramp 813 areused. In this alternate embodiment, the precleaner 815 is mounteddirectly onto the primary element 800, as opposed to the cover.

The remainder of the assembly utilized with respect to precleaner 800may be generally analogous to that described for the embodiment of FIGS.1-13, or for the alternate embodiments described.

Of course as a still further alternate, the cover 20, precleaner (135,815) and element (30, 200) could be made permanently connected to oneanother. Possible modifications to accomplish this will be apparent fromthe general teachings herein.

E. A Further Alternate Mounting Arrangement for the Cover, FIGS. 22 and23

Attention is now directed to FIG. 22 in which an air cleaner assembly900, comprising a housing 901 with a side wall 902 having a cover 920mounted thereon, as shown. The air cleaner 900 may be generallydescribed for the embodiments above, except as characterized in thissection. In particular, cover 920 includes, molded thereon, wire latchmounts 921. Cover 920 further includes wire latches 922, snap fitmounted to the mounts 921. As a result, when disengaged, the latches 922remain secured to the cover 920, when the cover 920 is removed from theremainder of the housing 901. When this function is conducted, the wirelatches 922 double as handles, to facilitate handling the cover 920.

The wire latches 922 shown, are configured to engage over a lip orsimilar structure of the housing 901, to project through slots 925, 926in the housing sidewall 902 and cover 920 respectively, FIG. 23, toprovide for a secure engagement.

Referring to FIG. 22, it is noted that analogously to the arrangement ofFIG. 1, the arrangement of FIG. 22 is a jointed housing 930, having twosections 931 and 932. The connection between the sections 931 and 932 isa modification, from the arrangement of FIG. 1, but uses the samegeneral principles. In particular, section 932 includes a skirt 933thereon, which overlaps and circumscribes a portion of section 931. Theskirt 933 includes apertures 934 therein radially spaced. Each aperture934 is sized to engage a projection 935 on section 931, for lockengagement. Thus, an interlock mechanism 936 is provided comprising aprojection (935) and receiver (934) arrangement.

A radial locater or indexed jointed mechanism arrangement using receiver938 in skirt 933, which overlaps a pin 939 on segment 931, is alsoprovided, similarly to the arrangement of FIG. 1.

It is also noted that the mounting mechanism 940 for the arrangement 900of FIG. 22, differs in detail from the analogous arrangement for theembodiment of FIG. 1. However, its overall operation is similar.

XII. The Embodiment of FIGS. 24-27

An improved embodiment is depicted in FIGS. 24-27. In FIG. 24, aircleaner assembly 1100 is depicted comprising a housing 1101. The housing1101 is generally analogous to housing 901, FIG. 22, except ascharacterized in this section. It is noted that the housing 1101 of FIG.24 is schematic.

Referring to FIG. 24, access or service cover 1110 differs from cover920, in that no central recess is present. Further, access or servicecover 1110 includes a notch 1111 associated with a key or pin 1112, at adifferent location, than the embodiment of FIG. 22. Also, underneathlatch 1120 access or service cover 1110 includes a notch or slot 1121,in outer rim 1122 for receipt of pin, key or projection 1123 on theremainder of the housing 1101. Thus, slot 1121/key 1123, along with slot1111/key 1112, provide for preferred rotational indexing between thecover 1110 and the remainder of the housing 1101.

Still referring to FIG. 24, mounting arrangement 1130, for securing thehousing 1101 to a vehicle or the equipment, is also modified from theembodiment of FIG. 22.

Attention is now directed to FIG. 25. Here the inside surface 1140 ofcover 1110 is viewable. It is noted that instead of having an “X” orplus-shaped (“+” shaped) projection, as shown for previous embodiments,the cover 1110 includes, along internal surface 1140, a projectionarrangement comprising four posts 1141 arranged as the corners of an “X”or plus-shape, to be received within a non-circular, preferably “X” orplus shaped recess, not shown, in the primary or main filter cartridge1145. With respect to this feature, cartridge 1145 may have an “X” orplus shaped receiver analogous to the cartridge depicted in FIG. 4. Theposts 1141 each have curved outside surfaces, approximately as half of acylinder, or cone to facilitate engagement. The four posts 1141 allowfor four possible rotational positions of the cartridge 1145. Of coursefewer posts (1, 2 or 3) could be used to accomplish the same type ofeffect, if properly positioned.

Still referring to FIG. 25, primary cartridge 1145 also includes centralcircular rib 1146 thereon. The rib 1146, as seen in FIG. 26, wouldpreferably extend completely around cartridge 1145 at a centrallocation, and in a direction generally orthogonal to a central axis ofthe cartridge 1145. The rib 1146 provides a projection that can beengaged by equipment, during manufacture. It is not expected that rib1146 will provide significant function, in the assembled and operatingair cleaner. However, it will add some strength to the open frame workaround the outside of primary cartridge 1145.

In FIG. 27, a cross-sectional view of the air cleaner assembly 1100 isshown. From a review of FIG. 27, it can be seen that a secondary orsafety filter 1150 for the assembly 1100 is constructed shorter than thesafety filter depicted in FIG. 2 at 31. Thus, at end 1151 filter 1150does not include a receiver, to engage protection 1152 in the primaryfilter cartridge 1145.

In FIG. 27, an improved alternative for securing the media in asecondary or safety filter 1150 is also provided. In particular, insafety filter 1150, the media 1155 is secured within the framework 1156,during molding. That is, the media 1155 is positioned in the mold, andthe plastic framework 1156 is molded but with the media 1155 in place.Thus, as shown, the spaced axial ribs 1157 of the safety filter 1150each have central portion where the conical media 1155 passes throughthem to extend between them over the openings 1158. Of course, if itdesired to use the framework of the safety filter 1150 without the media1155, the same molded configuration can be used, but without the mediapresent.

Referring to FIG. 24, it is noted that the housing 1101 does not includea rotational joint at seam 1160. It has been determined that duringmanufacture, the mold for housing 1101 can be constructed such that theportion in which region 1162 is molded, can be made rotatable relativeto the portion in which region 1163 is molded. Thus, variations inrotational orientation between the air inlet and the dust ejector outletcan be accommodated during the molding process, by using a methodinvolving a mold which has two parts rotatably moveably relative to oneanother. Seam 1160 is positioned with a joint between the two moldsegments would be located.

Referring to the cross section of FIG. 27, it is noted that the safetyelement 1150 includes o-ring seal 1170; and, an extension 1171positioned axially toward outlet 1175 for a remainder of the safetyelement 1150. Extension 1171 can facilitate mounting and engagement.

In other manners, the assembly 1100 may be constructed in accord withthe descriptions and variations presented herein, in association withother embodiments. Also, the improvements described for assembly 1100can be applied in the other embodiments.

XIII. The Embodiment of FIGS. 28-33

A further improved embodiment is depicted in FIGS. 28-33. The aircleaner assembly 1100 depicted in these Figs., and the subcomponentsthereof, may be generally analogous to the arrangements depicted inFIGS. 24-27 and in other previous Figs., discussed above. Focus in thissection will be with respect to certain specific preferred features. Itwill be understood, that, in general, components similarly positionedand depicted in the figures provide for analogous operation to those ofpreviously described figures.

In FIG. 28 an assembly 1500 is depicted, including a housing 1503 havingan air inlet 1505, an air outlet 1506, and dust ejector drop tube 1507.The assembly 1500 also includes optional mounting structure, legs orsupports 1508 thereon, to facilitate mounting. As with otherembodiments, the assembly could alternatively be mounted by a separatemounting band or bracket.

Referring to FIG. 28, the housing 1503 has first and second oppositeends 1516 and 1517. End 1516 is closed by a cover portion 1518 havingoutlet tube 1506, in this instance an axial outlet tube, projectingtherefrom. Referring to FIG. 28, for the embodiment shown cover 1518 isintegral with (i.e., is not separable from), end 1516.

End 1517, the other end, is generally an open, service, end closed byopenable cover 1520. The cover 1520 is removable, for service access toan interior of housing 1503.

The cover 1520 is secured in place by latches 1523 and 1524, mounted onmounts 1523 a and 1524 a, respectively. The cover 1520 is rotationallyindexed, by a rotational index or indexing arrangement, so that it canonly be secured in place at one orientation. For the cover 1520, indicia1525 is provided, to indicate a convenient orientation of the cover 1520during servicing. In particular, the indicia 1525 chosen, is an arrowthat points in the direction of the inlet 1505.

For the particular assembly 1500 depicted, portion 1500 a of the housingis secured to portion 1500 b, at seam 1500 c. Portion 1500 a isnon-rotatable relative to portion 1500 b. However the mold from whichthe two portions are formed, can be provided with a rotatable joint at aportion corresponding to 1500 c, so that the two pieces 1500 a and 1500b can be molded as a single unit, with any preferred rotationalorientation of section 1500 a relative to section 1500 b, that isdesired. Rotation is generally selected so that the inlet tube 1505 hasan orientation preferred for particular equipment which the air cleaner1500 is to be used. For the particular example shown in FIG. 28, theinlet tube 1505 projects in a direction parallel to the arrow of indicia1525, and in a general direction parallel to the direction of dust droptube 1507, although alternatives are possible.

Rotational indexing of the cover 1520 on the housing 1528, can beprovided by a variety of structures. Referring, for example, to FIG. 29,at open end 1517 housing 1503 is provided with outer key or projection1530 which, during assembly, is received within receiver or slot 1531 oncover 1520. Also, on cover 1520 a key or projection 1533 is provided,which is received within receiver or slot 1534 on housing 1503. Furtherthe cover 1520 includes thereon keys or projections 1536 and 1537, FIG.30, received within slots or receivers 1538 and 1539, respectively, FIG.29, during assembly. Finally receiver or slot 1540 is shown, FIG. 29, toreceive a similar key or projection to projections 1533, 1537, and 1536,appropriately rotationally positioned on cover 1520, FIG. 29, but notviewable.

Attention is directed to FIG. 30, which shows an inside surface 1540 ofcover 1520. Projecting centrally, internally, cover 1520 includes a plus(or “+”) shaped projection 1541, which, in use, is received within aplus (or “+”) shaped receiver, 1550 on a primary filter element 1551, inuse.

Referring to FIG. 30, the plus (or “+”) shaped projection 1541 depicted,has a generally hollow interior 1541 a and is open in direction towardan interior of air cleaner 1500.

Of course engagement between the plus (or “+”) shaped projection 1541and the plus (or “+”) shaped receiver 1550, prevents rotation of primaryelement 1551, after assembly and in operation. The plus (or “+”) shapeallows for four possible rotational orientations between the cover 1520and the primary element 1551, although alternatives are possible.

As indicated previously for other embodiments described, preferably aprojection analogous to projection 1541 is provided on an inside surface1540 of the cover 1520, to engage an appropriately shaped receiver on anend of the primary filter element 1551. The particular “+” shape chosen,is an example. Preferably the shape chosen will be one that does notallow rotation of the element 1551 relative to the cover 1520, onceengagement occurs. Thus, preferably the projection is not round, and thereceiver is not round.

Attention is directed to FIG. 29. For the particular embodiment shown,positioned to be received projecting inside of primary element 1551, issupport structure 1560. The support structure may be a component of asecondary filter element, or it may simply comprise framework to supportan interior of media contained within primary filter element 1551. Thus,support structure 1560 may be analogous to structure of safety element1150, described above in connection with FIGS. 24-27.

A difference between support structure 1560 and the previously depictedsupport structure, is provided at closed end 1561, FIG. 29. Inparticular, at closed end 1561, central recess 1563 is depicted, inextension across end 1561.

In general, it is anticipated that structure 1560 will be injectionmolded. A convenient location for introduction of plastic into theinjection mold, is in center 1564 of end piece 1561. Such a moldingoperation will leave a small projection or burr of plastic at center1564. Shaping the mold to form recess 1563, ensures that the burr orprojection of plastic at center 1564 is contained within the recess1563. This means that as an operator's hand is pressed against end 1561,burr 1564 is recessed, and provides less discomfort to the operatorduring installation.

Attention is now directed to FIG. 32, in which the serviceable primaryfilter element of 1551 is depicted in side elevation. In general, it hascomponentry similar to the embodiment described above in connection withFIGS. 24-27. That is, it includes an outer support structure 1580,preferably having an imperforate shield region 1581 and a porous,perforated or open region 1582, around which framework 1583 is provided.The element includes open end 1590, closed end 1591, and media 1592extending therebetween. Optional central circular projection 1593 is tofacilitate machine handling, during certain manufacturing steps.

The media 1592 may comprise a variety of types of media. For the exampleshown the media 1592 is pleated media 1594.

The particular primary filter element 1551 depicted, has a conicalshaped portion, thus at region 1595, the media 1592 is provided with aslightly larger outside diameter, than at end region 1596, analogouslyto previously described embodiments. The conical shape may be aspreviously described, for other embodiments.

At end 1590, a compressible axial seal gasket ring 1600 is depicted. Thering 1600 may be similar to ring or rib 70, FIG. 5, preferablycomprising a compressible polyurethane foam and preferably having ahardness of no greater than 30 Shore A.

Primary filter element 1551 also includes optional dust shield 1610thereon, as a circular outwardly projecting ring spaced from end 1590.This is analogous to structure shown in the embodiment of FIGS. 24-27.

Mounting structure 1620 is positioned on framework 1580 at a locationbetween shield 1610 and end 1600.

The mounting structure 1620 comprises spaced projections 1621,configured to operate analogously to spaced projections in the previousembodiments. Projections 1621, however, have a somewhat different shape,as viewable in FIG. 32, from the arrangement of FIG. 26.

In particular, projection 1621 includes opposite surfaces 1623, 1624extending between ends 1625 and 1626.

Surface 624 is configured to engage a projection or holder structure ina housing, during a twist lock operation to secure element 1551 inplace, analogously to the operation described above for otherembodiments.

Surface 1624, then, is preferably provided with a cam surface 1630,which recesses (in extension from tip 1625) toward dust ring 1610 or end1591, from end 1590. The cam surface 1630 ends at surface portion 1631which itself terminates at stop 1632. Thus, during operation, element1551 will be pushed into the housing, until tip 1625 passes a holder,lug or projection analogous to projections 140, FIG. 9. Rotation ofelement 1551 will bring tip 1625 around the projection, for engagementbetween cam surface 1630 and the projection. Continued rotation willbring the projection along surface 1631 until stop 1632 is encounteredby the holder, lug or projection in the housing.

Unlike the arrangement of FIG. 26, projections 1620 do not have tailsextending radially around surface 1640, toward a next adjacentprojection. This leaves a larger (relative) gap between end 1626 and atip 1625 of a next adjacent projection 1620. Preferably at an angularspacing of at least 20°, more preferably at least 35°-70°, is provided,for convenient assembly.

In FIG. 33, framework 1583, for forming primary filter element 1551 isdepicted. The framework 1583 of FIG. 33 could be analogous to theframework depicted in FIG. 26.

Still referring to FIG. 32, in general mounting structure 1620, then,comprises a portion of a non-continuously treaded rotationalinterlocking arrangement, when used in association with appropriateprojection or holder arrangement on a housing. Further, the mountingstructure 1620 comprises a segmented ring of projections or segments1621, each of which is radially spaced from a next adjacent one; and,each of which is preferably integral with (i.e., molded as part of)framework 1580. The number of projections, generally indicate the numberof rotational orientations possible for the primary element 1551, in ahousing 1503, FIG. 28.

In FIG. 33, outer framework or outer support structure 1580 usable toform primary filter element analogous to element 1551, FIG. 32, isdepicted. The framework 1580 may be used, in assembly, analogously tothe discussed above for FIG. 8.

With respect to FIG. 33, attention is directed to end 1640, to becovered by an end cap, in use. End 1640 has an open (or perforate)portion 1641 generated by framework 1642, in particular radial pieces1643 and central piece 1644.

In a central region end 1640 includes closed (imperforate) portion 1650having central receiver or recess 1645 therein. The particular centralrecess 1645 depicted, has a plus (or “+”) shape, for receiving aprojection on the cover in use.

In use of framework 1580, to manufacture an element, pleated media wouldbe positioned inside the framework 1580, with an end engaging framework1642. Potted end caps would be formed at the opposite ends 1640, 1670,with the end cap or potting at end 1670 being open, and defining theaxial seal 1600, FIG. 32. The media will be supported along an insideadjacent framework 1642, by surrounding central portion 1650, whichprojects into the open center of the framework 1580.

At end 1640, the material will be potted into end cap material (orpotting), to cover the opened area 1641, without covering the centralportion 1650 and recess 1645. The result would be structure analogous tothat shown and discussed above, for example with respect to FIG. 4.

For convenience, in FIG. 31 a cross-sectional view of assembly 1500,FIG. 28, is depicted. This view is analogous to the view of FIG. 3. Init, primary element 1551, support 1560, housing 1503 and cover 1520 areviewable.

Above it was mentioned that the inner support 1560, could comprise asupport of a secondary filter, for example as described above for otherembodiments.

Attention is now directed to FIG. 31. In FIG. 31, it can be seen thatwhen latched, the latches 1523 each include a projection 1523 b, whichextends through both a portion of the housing 1503 and a portion of thecover 1520, during latching. This is analogous to the arrangement shownabove, in FIG. 27.

Referring to FIG. 29, it is noted that inner support 1540 includeso-ring 1700 thereon, for sealing, radially, in the housing, during use.This sealing is depicted in FIG. 32.

XIV. Materials and Construction

Principles according to the present disclosure can be implemented in avariety of sizes, shapes and configurations of equipment, and using avariety of materials. However, the principles were developed forapplication in preferred arrangements and configurations, and withcertain preferred materials.

For example, in general the configurations shown will be particularlyadvantageous for use as an air cleaner for a vehicle having an air flowdemand, at rated operation, the order of about 1,500 cubic feet perminute (cfm) or less, typically about 300 cfm or less; i.e., on theorder of 43 cubic meters or less, typically about 9 cubic meters orless. These types of air cleaners are generally found on equipment thatuses small gas or small diesel engines.

The typical air cleaners used in such applications, would have anoverall outside diameter of the housing, on the order of at least 130mm., typically 130-170 mm.; and a housing sidewall length of at least300 mm. typically from 300 mm. to 600 mm. (i.e., distance between ends16 and 17), FIG. 1. The outer support 90 of primary filter cartridge 30,would have a largest outside diameter D1, of at least 120 mm., andsmallest outside diameter D2 on the order of about 110 mm. or less, witha conical angle or taper (i.e., angle A, FIG. 6, where dotted line 950is parallel to central axis 12, FIG. 3) between the ends, extending atan angle on an order of at least 1° typically within the range of 2° to4°, and with an overall length of at least 100 mm. and typically 110-150mm. The aperture 102, FIG. 8, would have a diameter of at least 115 mm.,typically 118 mm. to 125 mm.

In general, dimension materials for the rib 70 and the interlockarrangement 129, should be selected to provide for a compression of rib70 of at least 0.5 mm., typically 1-2 mm., in use. The desirablematerial for rib 70, and indeed end cap 92, is a foamed polyurethanepreferably to be selected to have a hardness, Shore A, of no greaterthan about 30, and preferably no greater than about 22, most preferablybelow 20.

Preferably with such arrangements, the polyurethane formulation chosenprovides for a high foam, very soft, molded end cap.

Preferably the formula chosen will be such as to provide end caps (partsmolded from the polyurethane) having an as molded density of no greaterthan 28 lbs./cubic foot (about 450 kilograms/cubic meter), morepreferably no more than 22 lbs./cubic foot (355 kilograms/cubic meter),typically no greater than 18 lbs/cubic foot (290 kilograms/cubic meter)and preferably within the range of 13 to 17 lbs/cubic foot (208-275kilograms/cubic meter).

Herein the term “as molded density” is meant to refer to its normaldefinition of weight divided by volume. A water displacement test orsimilar test can be utilized to determine volume of a sample of themolded foam. It is not necessary when applying the volume test, topursue water absorption into the pores of the porous material, and todisplace the air the pores represent. Thus, the water volumedisplacement test used, to determine sample volume, would be animmediate displacement, without waiting for a long period to displaceair within the material pores. Alternately stated, only the volumerepresented by the outer perimeter of the sample need be used for the asmolded density calculation.

In general, compression load deflection is a physical characteristicthat indicates firmness, i.e. resistance to compression. In general, itis measured in terms of the amount of pressure required to deflect agiven sample of 25% of its thickness. Compression load deflection testscan be conducted in accord with ASTM 3574, incorporated herein byreference. In general, compression load deflection may be evaluated inconnection with aged samples. A typical technique is to measure thecompression load deflection on samples that have been fully cured for 72hours at 75° F. or forced cured at 190° F. for 5 hours.

Preferred materials will be ones which when molded, show a compressionload deflection, in accord with ASTM 3574, on a sample measured afterheat aging at 158° F. for seven days, on average, of 14 psi or less,typically within the range of 6-14 psi, and preferably within the rangeof 7-10 psi.

Compression set is an evaluation of the extent to which a sample of thematerial (that is subjected to compression of the defined type and underdefined conditions), returns to its previous thickness or height whenthe compression forces are removed. Conditions for evaluatingcompression set on urethane materials are also provided in ASTM 3574.

Typical desirable materials will be ones which, upon cure, provide amaterial that has a compression set of no more than about 18%, andtypically about 8-13%, when measured on a sample compressed to 50% ofits height and held at that compression at a temperature of 180° F. for22 hours.

In general, the compression load deflection and compression setcharacteristics can be measured on sample plugs prepared from the sameresin as used to form the end cap, or on sample cut from the end cap.Typically, industrial processing methods will involve regularly makingtest sample plugs made from the resin material, rather than directtesting on portions cut from molded end caps.

Urethane resin systems useable to provide materials having physicalproperties within the as molded density, compression set and compressionload deflection definition as provided above, can be readily obtainedfrom a variety of polyurethane resin formulators, including suchsuppliers as BASF Corp., Wyandotte Mich., 48192.

One example usable material includes the following polyurethane,processed to an end product having an “as molded” density of 14-22pounds per cubic foot (224-353 kilograms/cubic meter). The polyurethanecomprises a material made with I36070R resin and I305OU isocyanate,which are sold exclusively to the assignee Donaldson by BASFCorporation, Wyandotte, Mich. 48192.

The materials would typically be mixed in a mix ratio of 100 partsI36070R resin to 45.5 parts I3050U isocyanate (by weight). The specificgravity of the resin is 1.04 (8.7 lbs/gallon) and for the isocyanate itis 1.20 (10 lbs/gallon). The materials are typically mixed with a highdynamic shear mixer. The component temperatures should be 70-95° F. Themold temperatures should be 115-135° F.

The resin material I36070R has the following description:

-   -   (a) Average molecular weight        -   1) Base polyether polyol=500-15,000        -   2) Diols=0-10,000        -   3) Triols=500-15,000    -   (b) Average functionality        -   1) total system=1.5-3.2    -   (c) Hydroxyl number        -   1) total systems=100-300    -   (d) Catalysts        -   1) amine=Air Products 0.1-3.0 PPH    -   (e) Surfactants        -   1) total system=0.1-2.0 PPH    -   (f) Water        -   1) total system=0.2-0.5%    -   (g) Pigments/dyes        -   1) total system=1-5% carbon black    -   (h) Blowing agent        -   1) water.

The 13050U isocyanate description is as follows:

-   -   (a) NCO content—22.4-23.4 wt %    -   (b) Viscosity, cps at 25° C.=600-800    -   (c) Density=1.21 g/cm³ at 25° C.    -   (d) Initial boiling pt.—190° C. at 5 mm Hg    -   (e) Vapor pressure=0.0002 Hg at 25° C.    -   (f) Appearance—colorless liquid    -   (g) Flash point (Densky-Martins closed cup)=200° C.

The material selected for the media may be varied, depending on theanticipated environment of use and availability of various pleatablesubstrates.

Conventional media available from such suppliers as Hollingsworth andVose of East Walpole, Mass. can be utilized. It is anticipated that intypical arrangements, pleats 85 in the order of ⅜ inch to 3 inches (0.9cm to 7.6 cm) in depth, with a pleat population, around the innerdiameter, of about 10 to 14 per inch at the larger diameter end (15 to20 per inch at the smaller diameter end) with a conical unit being used.

The principal structural component of the primary filter cartridge 30,i.e., support 90, will generally be made from a rigid plastic such as aglass filled nylon (for example 33% glass filled nylon 6/6, 1.5 mm.thick). Such a component could generally be made by a plastic moldingoperation, for example injection molding.

Support structure 160, which operates as either an inner support for theprimary filter cartridge 30 or as both an inner support for the primaryfilter cartridge 30 and an outer support for a optional safety cartridge31, will generally be formed from a rigid plastic similar to that usedfor support 90 formed using a similar molding process. The media 65 orthe safety filter cartridge 31 is a matter of preference for theparticular application, and it would typically be non-pleated media witha side coated with a selected surface modifier, such as a tackifier.

Preferably both the primary filter cartridge and the secondary filtercartridge at least 98%, by weight, metal free, most preferably 100%metal free.

The housing sidewall segments 261 and 262 (or for the embodiment 300 ofFIG. 14, sidewall segment 301), are preferably molded from plasticmaterials such as a glass filled nylon (for example 33% glass fillednylon 6/6, 2 mm. thick). For these components an injection moldingprocess could be used. Preferably each of the components (except wherepossibly reinforced by a metal grommet to receive bolts for connectionto other components such as a truck frame and/or the latches) is atleast 98%, by weight, metal free, preferably 100% metal free. Metalgrommets might be utilized, for example, inside of mounting legs 8 ortap 6 a.

Cover 20 for the particular preferred embodiment shown, is sized andshaped so that it can be molded from plastic materials. It isanticipated that in general the precleaner 35, comprising shield 37 andramp 36, would be premolded for example from glass filled nylon orpolypropylene by an injection molding process, and would then beattached to a remainder of the cover 20, for example by heat staking,with an adhesive or with a snap (mechanical) fit.

The remainder of the cover 20, would preferably be molded from the samematerial as used for housing segments 261, 262, in an injection moldingprocess. The latches 171 could be molded integrally with cover 20 insuch a process. The cover 20 is preferably at least 98% metal free, mostpreferably 100% metal free.

The inlet tube 5 would typically have an inside diameter on the order ofabout 50 to 200 mm., for example about 60 mm., and the outlet tube 6would have an inside diameter of about the same. The down tube 7 wouldhave an inside diameter on the order of about 45 to 55 mm., for exampleabout 51 mm.

Typically and preferably the ramp 36 would extend through a rotation ofabout 150°-280° from end 400 to end 401, FIG. 5, and would extendlongitudinally along sidewall 9 over a distance of at least as wide asthe diameter of the entrance to tube 5, preferably slightly more.

The above dimensions, materials and specific described shapes, are meantto be exemplary only, and are not intended to be limiting unlessspecifically characterized as such in a claim. It will be apparent fromthe above, however, how the various techniques and improvementsdescribed herein can be applied in a wide variety of contexts andspecific applications.

The Applicant(s) specifically reserve the right to later claimembodiments and features currently disclosed but not claimed in thefollowing claims.

1. A filter cartridge comprising: (a) first and second, opposite, endcaps; (i) the first end cap being a molded-in-place end cap having anair flow exit aperture therethrough; (ii) the first end cap having ahousing seal comprising an integrally molded portion of the first,molded, end cap; (iii) the first end cap comprising foamed polyurethanehaving an as-molded density of no greater than 28 lbs/cu·ft.; (b) filtermedia embedded in, and extending between, the first and second end caps;(i) the filter media defines a conical shape in extension between thefirst and second end caps with a larger diameter adjacent the first endcap; (c) an outer framework having a sidewall structure circumscribingthe media at least at a location adjacent the first end cap; (i) theouter framework including an imperforate shield section adjacent thefirst end cap and extending an axial distance of at least 10% and notmore than 40% of a distance between the first end cap and the second endcap; and (ii) the outer framework including a dust shield positioned andoriented as a circular, radially outwardly projecting, ring.
 2. A filtercartridge according to claim 1 wherein: (a) the filter media comprisespleated media.
 3. A filter cartridge according to claim 2 wherein: (a)the first end cap comprises foamed polyurethane having an as-moldeddensity of no greater than 18 lbs/cu·ft.
 4. A filter cartridge accordingto claim 2 wherein: (a) the first end cap comprises foamed polyurethanehaving a hardness, Shore A, of below
 20. 5. A filter cartridge accordingto claim 2 wherein: (a) the outer framework extends completely betweenthe first end cap and the second end cap and includes a perforatesection that is at least 50% open in extension between the imperforateshield section and the second end cap.
 6. A filter cartridge accordingto claim 5 wherein: (a) the outer framework includes a conical shapedportion with a portion adjacent the first end cap having a larger outerdiameter than a portion adjacent the second end cap; (i) the conicalshaped portion of the outer framework having a conical angle within therange of 1° to 4°.
 7. A filter cartridge according to claim 6 wherein:(a) the filter cartridge includes no inner liner extending completelybetween the first and second end caps.
 8. A filter cartridge accordingto claim 7 wherein: (a) the filter cartridge is at least 98%, by weight,metal free.
 9. A filter cartridge according to claim 8 wherein: (a) thehousing seal comprises an axial seal.
 10. A filter cartridge accordingto claim 1 wherein: (a) the second end cap includes a central recesstherein.
 11. A filter cartridge according to claim 10 wherein: (a) thecentral recess is plus shaped.
 12. An air cleaner assembly comprising:(a) a housing having a sidewall and first and second opposite ends; (i)the first end being closed and having an axial outlet tube therein; (ii)the housing including a dust drop tube adjacent the first end; (iii) thehousing sidewall second end being an open end; and (iv) the housinghaving an end cover removeably mounted to close the housing second end;(A) the end cover having a precleaner comprising a shield having aspiral ramp on an outer surface thereof; (b) the housing including anair flow inlet positioned to direct air into the precleaner; and, (c) aconical, removable and replaceable, primary filter cartridge positionedwithin the housing with: (a) a larger diameter end of the primary filtercartridge sealed to the housing; and, (b) a narrow end of the primaryfilter cartridge surrounded by the precleaner.
 13. An air cleanerassembly according to claim 12 wherein: (a) the primary filter cartridgeincludes an open end cap adjacent the larger diameter end; (i) the openend cap comprising foamed polyurethane and including a housing seal. 14.An air cleaner assembly according to claim 13 wherein: (a) the narrowend of the primary filter cartridge includes a closed end cap with acentral recess.
 15. An air cleaner assembly according to claim 14wherein: (a) the end cover of the housing includes a portion projectinginto the central recess of the primary filter cartridge closed end cap.16. An air cleaner assembly according to claim 12 wherein: (a) theprimary filter cartridge includes a dust shield positioned as acircular, radially outwardly projecting, dust ring; (i) the dust ringbeing positioned adjacent the dust drop tube.
 17. An air cleanerassembly according to claim 16 wherein: (a) the air flow inlet is a sideinlet positioned in the housing sidewall.
 18. An air cleaner assemblyaccording to claim 12 wherein: (a) the primary filter cartridge issealed to the housing with an axial seal.